This invention relates to solar synchronization of clocks and solar event triggering mechanisms.
There are numerous ancient examples of solar event triggering mechanisms. The most famous example is Stonehenge. This and other similar structures provided a specific site where specific sidereal events could be tracked, usually the summer and winter solstices. Such structures were incapable of triggering on a diurnal solar event. Further, such structures were incapable of providing a mechanical trigger to such diurnal solar events.
Not only are there numerous ancient solar clocks, but there is also a family of xe2x80x9csun dialsxe2x80x9d of varying accuracy. These devices provide an approximate estimate of the sidereal time, but are incapable of providing a mechanical trigger based upon daily or diurnal solar event such as sidereal noon. Such devices are further incapable of mechanically triggering on the visibility of such diuranl solar events.
Solar energy has been known, since the time of Archimedes, to be able to trigger mechanical events. Plutarch records that during the battle of Syracuse, a group of soldiers under Archimedes"" direction focused the reflection of the sun off the insides of their polished bronze shields to cause fires on the ships of a Roman fleet attacking Syracuse.
Beyond the historical importance of this first recorded example of solar power engineering, there are common characteristics to be considered. The shields needed the men to aim them at the ship to be burned. Without an aiming or tracking mechanism there would have been no mechanical event, no matter how much solar energy was available. This is a consistent theme throughout the history of solar power usage, leading to the solar tracking mechanisms in use today.
There are reports of a xe2x80x9cTurkish canonxe2x80x9d, which consisted of a canon whose ignition cord was aligned with a magnifying lens so that it lit shortly before sidereal noon. The ignition cord burned and ignited the charge shortly thereafter, at noon. This system could detect a diurnal solar event, sidereal noon, but it was incapable of being used repeatedly at such a task.
More recently, solar tracking mechanisms have been deployed to align solar engines and photocell arrays with the motion of the brightest point or region in the sky. These mechanisms often include two connected chambers mounted on either of two opposing sides of the engine or array. The entire assembly is on a pivot. The chambers have a heat absorbent coating and are filled with a low boiling point fluid. The chambers are placed on opposite sides of the engine or array with blinders so whichever one is further away from the solar hot spot is in the shade. The chamber in the sunlight absorbs heat causing the fluid to boil and condense in the shaded chamber, making it heavier, which causes the assembly to tilt in that direction through the pivot.
This tracking mechanism is very good at following the hotspot of the sky throughout a day, but it does not have the ability to determine a specific solar event reliably. It cannot determine the time of day, or whether the sun is essentially visible at that time of day.
Other tracking and switching mechanisms include a variety of photo-cells often combined with computer systems circuits. Such systems have been used to turn on lights as evening approaches and charge batteries from solar cells when the day becomes bright enough. Again, such systems cannot determine the time of day, or whether the sun is essentially visible at that time of day.
Other similar applications include a solar cell powering a motor controlling blinds. When the sun comes up, or the sky is bright enough, the motor acts to control the blinds. When the sky becomes dark enough, the motor acts to control the blinds in a second manner. Again, such systems cannot determine the time of day, or whether the sun is essentially visible at that time of day.
What is needed is a mechanism which, without intervention or supervision, can determine whether the sun is visible during a specific diurnal solar event and mechanically trigger actions based upon the sun being visible during that diurnal solar event.
This invention provides mechanisms determining whether the sun is visible at a diurnal solar event and mechanically triggering actions based upon the sun being visible during the diurnal solar event. The mechanisms of the invention can perform these operations without intervention or supervision for long periods of time. Certain embodiments have been applied to provide a diurnal solar event trigger based upon sidereal noon for a clock whose purpose is to provide accurate timing for 10,000 years without intervention or supervision.
Certain embodiments of the invention include a mechanism activating a synchronization lever whenever a diurnal solar event is visible. The mechanism comprises a solar portal coupled to the synchronization lever, activating the synchronization lever whenever the diurnal solar event is visible at the solar portal. Such embodiments advantageously support a solar portal activating the synchronization lever whenever the diurnal solar event is visible.
The solar portal may further comprise a slot positioned so sunlight strikes a target whenever the diurnal solar event is visible at the solar portal. The target couples to the synchronization lever, activating the synchronization lever whenever the diurnal solar event is visible at the solar portal. Such embodiments advantageously support a slot positioned so sunlight strikes a target whenever the diurnal solar event is visible and the target activates the synchronization lever.
The mechanism may further comprise a solar concentrator concentrating sunlight striking the target whenever the diurnal solar event is visible at the solar portal. Such embodiments advantageously support the mechanism further comprising a solar concentrator which concentrates sunlight on the target whenever the diurnal solar event is visible at the solar portal.
The solar concentrator may be comprised of a lens aligned with the slot concentrating sunlight striking the target whenever the diurnal solar event is visible at the solar portal. Such embodiments advantageously support the solar concentrator including a lens.
The solar concentrator may also be comprised of a mirror aligned with the slot concentrating sunlight striking the target whenever the solar event is visible at the solar portal. Such embodiments advantageously support the solar concentrator including a mirror.
The target may be further comprised of the following. A strip formed of a first material coupled to the synchronization lever and largely positioned within the target. The strip is comprised of a first end and a second end. And a support formed of a second material anchoring the first end and anchoring the second end and positioned outside the target so that sunlight does not strike the support during the diurnal solar event. The target activating the synchronization lever is further comprised of the strip activating the synchronization lever by expanding whenever the diurnal synchronization event is visible at the solar portal. Such embodiments advantageously support a strip anchored at two ends by a support activating the synchronization lever by expanding whenever the diurnal synchronization event is visible at the solar portal.
The first material has a significant and nearly uniform first coefficient of expansion across an operational temperature range. And the second material has essentially the same nearly uniform coefficient of expansion as the first coefficient of expansion across the operational temperature range. Such embodiments advantageously provide for the support expanding at essentially the same thermal rate of expansion as the strip, providing a cancellation of ambient temperature effects.
The strip may be comprised of a dark coating over at least most of the strip receiving the sunlight during the diurnal solar event. Such embodiments advantageously support a dark coating over most of the strip receiving sunlight during the diurnal solar event.
The diurnal solar event may comprise a sidereal time interval close to sidereal noon. The sidereal time interval may be within three hours of sidereal noon.
The sidereal time interval may have duration of greater than a second. The sidereal time interval may have duration of greater than a minute. The sidereal time interval may have duration of greater than an hour. Such embodiments advantageously support diurnal solar events with various interval lengths.